Labour has acknowledged Sir Keir Starmer “misheard” an allegation from the Prime Minister that triggered a Commons row between the pair.
Sir Keir accused Boris Johnson of talking “complete nonsense” after the Prime Minister accused the Labour leader of repeatedly calling for the UK to stay in the European Medicines Agency (EMA) after Brexit, suggesting such a move would have hampered the country’s Covid-19 vaccine rollout.
The Opposition leader and Mr Johnson were seen walking out of the Commons together following the Prime Minister’s Questions clash and continued their conversation while standing just outside the Chamber.
But Mr Matheson called the eyewitnesses’ claims “absolute bollocks”, adding: “There was a brief chat and then Keir and I left together.
“Nothing more to it than that.”
A Labour source said: “They had a perfectly reasonable conversation as they often do after PMQs.”
It later emerged Sir Keir thought the Prime Minister was accusing him of wanting to be part of the EU’s vaccine scheme, which is lagging behind the UK’s.
A spokesman for the Labour leader said: “On a number of occasions the Prime Minister has wrongly claimed that Labour wanted to join the EU’s vaccine programme. That is inaccurate and the claim has been found to be untrue.
“This afternoon during Prime Minister’s Questions, Keir misheard the Prime Minister and assumed he was making the same false accusation again.
“Keir accepts that, on this occasion, the Prime Minister was referring to old comments about the European Medicines Agency and Keir admits he was wrong and made a mistake in his response.
“It’s not Labour policy to join either the European Medicines Agency or the EU vaccine programme.
“We have never called for the UK to be in the EU vaccine programme. We remain committed to working with the Government to ensure we can be the first in the world to roll out the vaccine.”
Hansard, the official record of Parliament, shows that in January 2017 Sir Keir questioned why the UK would want to leave the EMA, Europe’s medicines regulator, and that it should be something retained as part of the Brexit process.